Pretty much in agreement with everything K said. I tweak a few settings for extra battery life, Usually charge it overnight, every night. Mine doesn't often run completely flat, but I do spend a lot of time on the web with it. T-Mobile is pretty good service-wise in the U.K., rarely any dropped calls or late arriving texts. GPS is the major battery hog, which is unfortunate, as there are some really fun GPS apps out there, and even just allowing the Google homepage access to your GPS co-ords can be helpful.
The Bluetooth wasn't any use for transferring pictures, sounds and other files between phones, which is what I miss from that, but I haven't tried since the Cupcake update. It is fine with a BT handsfree car set, though.
Don't get the white version of K's phone, that is the one I have (I refused to wait an extra week or two until they got more black stock) and the keyboard on that one is harder to read when it illuminates. The black one doesn't look like it would have that problem, which comes from the gray colour of the keys on the white model.